There are many well-known antimicrobial compositions. For example, such antimicrobial compositions include conventional treatments such as antiseptics and antibiotics. However, there are many potential and real adverse effects associated with the clinical use of such antimicrobial compositions. Adverse effects associated with the use of antibiotics include allergic reactions, destruction of beneficial microflora, development of resistant species of micro-organisms, immune suppression, overgrowth of Candida albicans and undesirable intestinal flora, development of chronic fatigue syndrome and nutrient loss which can result in a nutrient deficiency state. The degree to which these adverse effects are realized is usually dependent on the concentration of antimicrobial administered.
One of the most important of these adverse side effects, is the emergence of antibiotic resistance. The continued emergence of antibiotic resistant pathogens is a serious threat to controlling infections and provides a convincing reason to develop new therapies designed to overcome this problem. Any treatment which overcomes or ameliorates this significant adverse side effect would be desirable.
Furthermore, the side effects associated with the use of potent and potentially toxic antibiotics cannot be overlooked. Again, any treatment which overcomes or ameliorates these adverse side effects would be desirable.
Another conventional treatment used in the treatment of mild to moderate acne vulgaris, is the combination of an antibiotic and benzoyl peroxide. There is now considerable literature on the use of benzoyl peroxide for the treatment of acne and its increased efficacy in combination with antibiotics, particularly erythromycin. This combination therapy has been found to provide an enhanced efficacy over the individual agents, with the potential to decrease the emergence of resistant strains of P. acnes. (Bowman, S., Gold, M., Nasir, A., and Vamvakias, G. Comparison of clindamycin/benzoyl peroxide, tretinoin plus clindamycin, and the combination of clindamycin/benzoyl peroxide and tretinoin plus clindamycin in the treatment of acne vulgaris: a randomized, blinded study. Journal of Drugs in Dermatology, September-October, 2005).
Furthermore, for example U.S. Pat. No. 4,497,794 is directed to the use of benzoyl peroxide and erythromycin. All the examples in this US patent relate to the use of benzoyl peroxide and erythromycin only. Other publications, relating to the use of benzoyl peroxide and erythromycin include Burkhart C N, Specht K Neckers D, “Synergistic activity of benzoyl peroxide and erythromycin”; Skin Pharmacol Appl Skin Physiol.: 2000 September-October; 13(5):292-6 and Eady E A, Farmery M R, Ross J I, Cove J H, Cunliffe W J. “Effects of benzoyl peroxide and erythromycin alone and in combination against antibiotic-sensitive and-resistant skin bacteria from acne patients”. Br J Dermatol. 1994 September; 131(3):331-6. Both these publications state that the combination of benzoyl peroxide and erythromycin is not synergistic and that the increased benefit is due to the benzoyl peroxide additionally killing the erythromycin-resistant strains. Finally, International Patent publication no. 96/10998 is directed to a topical treatment for acne comprising a peroxide and antibiotic of the lincomycin family. Again, all the examples in this patent relate to the use of benzoyl peroxide only.
Other antimicrobial treatments include silver-containing gels, compounds containing heavy metals and solutions of hydrogen peroxide and natural and synthetic pharmaceutically active substances. However, even these treatments have side effects, for example, high levels of hydrogen peroxide have a toxic effect. In addition, hydrogen peroxide in solution is typically unstable and it is difficult to provide a sustained delivery system for this material.
Additionally, in recent years there has been a resurgence of interest in the therapeutic efficacy of honey, particularly in the area of wound healing. As a natural product, honey offers an attractive alternative to conventional treatments. Many different types of honey have antimicrobial activity. Over the past number of years Manuka honey has been recognised as having superior activity to most other honeys. Manuka honey is known for the treatment of wound infections and its antibacterial activity. However, natural honey as an antibacterial agent has several disadvantages. Firstly, natural honey is composed of a diverse mixture of identified and unidentified organic and inorganic compounds at various concentrations. In this respect it can be expected to demonstrate a degree of variability which may be unacceptable for its use in many clinical applications. Secondly, honey is mainly used for topical application. This is because when honey is diluted by, for example, absorption into the gut it becomes too diluted to have any detectable activity. Finally, honey is a natural product, which will have many additional compounds present and some of these compounds may give rise to an allergic reaction when it is applied.
Thus, for a wide variety of different reasons, conventional antimicrobial treatments available to date have many drawbacks. Thus, there is therefore a need for improved antimicrobial systems which overcome the above-mentioned disadvantages.